Mine bet isn't

But if it is, then the bottom treatment is less than trivial.

Aluminum hulls on 45' boats are kind of rare, at least in my waters (I
have no idea if they're usual in Fla.). Aluminum is lower on the
galvanic series than copper, so if you have an aluminum hull you can't
use a copper based bottom paint, and even something as trivial as a
penny dropped into the bilge can do some serious damage to the hull.
This isn't real problem with a 15' trailerable dinghy or with a 150'
research vessel that has a 2" thick hull, but with boats in the 50'
range, it can be (in particular, I know of a 45' racing sailboat built
with a honeycomb core Al hull that is incredibly susceptable to
corrosion. The owner of this boat actually makes you empty your pockets
before boarding to make sure you don't have any pennies. One could
cause a hole in the hull). Tributultin is the preferred antifoulant for
Al hulls, but this is illegal for boats under 150' in the US and
irrelavant for boats that aren't kept in the water, such as a 15'
skiff. 50' Al boats require a a fair amount of regular maintenanceto
keep them clean. If this is really a 45' boat with an Al hull, then one
inch barnacles imply quite a bit of neglect and I'd be cautious about
applying too much force or abrasion to clean the bottom. Sinking the
boat while cleaning it is frowned upon ;-)

As for the diving details, the advice to inflate your BC and let this
push you up against the hull isn't a good way to clean a hull. Cleaning
hulls *is* crappy work, but the best way is to be as neutral as
possible. The pros keep their tanks and first stages on the pier, and
dive with a really hose between their first and second stages, making
themselves as light as possible. Barring that, strip everything from
your BC, and weight yourself to be as neutral as possible. It will be a
challenge to keep yourself close the hull while you push against it to
clean it,, but that's the challenge, and one reason why you want to
keep the hull as clean as possible if it's to be cleaned in the water.
Overbuoyancy won't help (most of the hull surface isn't horizontal), so
being neutrally buoyant will make it a little easier to keep yourself
against the hull (although nothing is going to make it easier).

Bottom line - you might be taking on a really big task that you
shouldn't take on, for a variety of reasons. You might also be agreeing
to help out someone who has maintained his boat very well and just
needs some regular, routine help. If it's the former, be prepared to
bail quickly. If it's the latter, then be prepared to spend two to four
hours scrubbing the hull with scotchbrite pads and other tools. If you
want to make a habit of this, then plan to invest in a 75-100' second
stage hose, along with a regulator set designated just for hull
cleaning.

Alan

Am I being ultra-cynical in thinking that this post was a neat piece of
product placement for the Speedblade product?

Benedict.

Mel said

Hmmm!
Amazing product is it?
The Wests in my town is attatched to a big boat yard so I should be
seeing them in heavy use throughout when I go there tomorrow. We'll see
what the pros say about it.